1. Field of the Invention
The invention relates to a lamp. Particularly, the invention relates to a lamp in which a housing of the lamp is capable of rotating relative to a bulb base.
2. Description of Related Art
In daily life, people usually use a table lamp to illuminate an area lacking of indoor light. For example, an area with inadequate illumination such as a desk or a table can be reinforced by using a table lamp, so that a user can read or engage in other works without worrying deterioration of eyesight caused by inadequate working environment light.
In order to enhance evenness of a light source, a commonly used table lamp in the market generally includes an optical plate, and the optical plate is assembled with a light-emitting device to form a module. A most easy manner of assembling the module to a base is to respectively configure a thread portion on the module and the base, and then the module is manually screwed to the thread portion. However, after the module is screwed to a fixed position, if an angle of a light-emerging surface of the table lamp is not an irradiation angle required by the user, the lamp is required to be reassembled, or is forcibly rotated to a desired position, which is inconvenient in utilization and is liable to cause a damage of the base.